It has been common to use a calender roller apparatus on sliver coiling devices having a pair of adjacent rotatable rollers between which a sliver is tensioned for delivery. It is necessary to have some means of biasing the rolls toward each other to determine the extent to which the sliver is compressed during its passage between the rolls so as to control the weight and length of the sliver which is deposited in the coiler can.
Heretofore resilient biasing devices have been used to bias the rollers towards each other, such as the spring clip used in U.S. Pat. No. 2,876,502. However, the problem with such a device is that if the sliver breaks and the loose end is lapped around the roller surface the sliver buildup may cause the rollers to spread apart with operational breakage to the roller assembly. Another problem which can arise is that the sliver will sometimes pile up in the flow tube beneath the rollers causing the sliver to choke beneath the surface of the rollers which can also cause operational breakage of the rollers if the biasing means does not release, or the pivoted roller is otherwise prevented from flipping up.
Other prior devices have been developed for releasing the pivoted roller when the thickness of the sliver between the rollers exceeds a predetermined depth. Such a device is shown in U.S. Pat. No. 3,443,282 wherein a latching lever is provided to latch the rollers apart in a spread position when the thickness of the sliver between the rollers exceeds a predetermined depth. However, when the rollers are run on high speed coiling machinery the pivoted roller tends to flip up in the absence of a more positive lock-down means due to the tension between the trumpet which feeds the sliver in the rollers.
Another prior device which attempts to use a more positive lock-down means for biasing the rollers together is shown in U.S. Pat. No. 3,391,427 wherein a pivoted latch is attached at one end to the pivotable roller member, and the other end of the latch slides over and abuts a spring bias plunging member for biasing the two rollers towards each other. The latching member is designed to release and hence allow the rollers to separate when excessive sliver buildup occurs between the rollers and at the same time to hold the rollers together in a positive manner. However, should the sliver strand become broken and a broken end thereof adhere to one of the rollers the sliver buildup can spread the rollers to such an extent as to possibly twist the pivoted roller about its pivot support before the latching member is released causing breakage at the pivot point. If the sliver chokes in the tube beneath the rollers the pile up of sliver beneath the surface of the two rollers could also possibly exert a sufficient upward force on the roller assembly to cause possible breakage before the latching member is released.
Accordingly, an important object of the present invention is to provide a coiler calender roller apparatus which will uniformly compress a sliver being passed for delivery between the rollers.
Another important object of the present invention is to provide a calender roller apparatus which can be run on a high speed sliver coiler without the need of a positive lockdown latch.
Another important object of the present invention is to provide a coiler calender roller apparatus wherein a pivoted roller is automatically released when slivers build up either beneath or around the rollers, thus preventing breakage of the roller assembly.
Another important object of the present invention is to provide a coiler calender roller apparatus wherein one of the rollers is pivoted and wherein the pivoted roller may be adjusted on its support to provide an adjustable biasing force between the rollers.
Another important object of the present invention is to provide a simplified coiler calender roller apparatus which is easy and simple to operate and which provides easy and quick access to any sliver buildup by the machine operator.